OUTLINE Introduction Experiment Concept Experiment Examples Explanation of Results Recommendations Questions

INTRODUCTION Reasons for experiment and presentation –Digitizing is what we do –Personal evaluation of best conversion methods –Video is a very complex subject – Engineering/ Mathematics/ Computer Science

BEFORE WE START…. Lets take a minute talk about our previous knowledge of Video Production Video Conversion

EXPERIMENT CONCEPT Converting VHS to DVD Utilizing consumer level products Choosing three different methods Analyzing results

WHY CONVERT Inherently self detrimental Low life expectancy Obsolete players

VHS DEGRADATION Playback causes damage –Loss of magnetism –Loss of emulsion –Tape stretching

LIFE EXPECTANCY Low life expectancy years Optimal condition – Particle free – degrees – 30% to 70% constant RH

VHS OBSOLETE! Most electronics stores only carry a few VHS players. Quality players are becoming harder to find

Now that we know why, How do we do it?

CONSUMER PRODUCTS VHS to DVD Recorders Conversion boxes Camcorders

VHS TO DVD RECORDERS One touch dubbing Record as well as playback Reasonably priced $80-$400

CONVERSION BOXES Compact Transfers any analog signal to digital –VHS to Camcorder –VHS to DVR –VHS to Computer –Wide price range $17-$1500

CAMCORDERS Conversion Record Playback Back up on digital tape Several models and prices Can be output to other devices –TV,VHS,DVR or Computer

CONVERSION METHODS DVD Recorder /Sony RDR-VX515 Conversion Box/ Canopus 100 Lower priced Camcorder/Canon ZR700 High Priced Camcorder/ Canon GL1

ANALYSIS PROCESS Use each method to convert VHS to DVD Analize DVD footage for –Picture quality –Color quality –Digital Artifacts

DVD RECORDER EXAMPLE

CONVERSION BOX EXAMPLE

LOW PRICED CAMCORDER EXAMPLE

HIGH PRICED CAMCORDER EXAMPLE

COMPARISON CanopusSony Recorder

COMPARISON CanopusSony Recorder

COMPARISON CanopusSony Recorder

COMPARISON CanopusSony Recorder X-30,y-20 = R140,G143,B153X-30,y-20 = R149,G140,B157

CAMCORDERS Canon ZR700 Canon GL1

CAMCORDERS Canon ZR700Canon GL1

CAMCORDERS Canon GL1Canon ZR700

CAMCORDERS Canon GL1Canon ZR700 X-30,y-20 = R172,G172,B184X-30,y-20 = R177,G181,B190

ALL FOUR Sony Recorder -> <- Canopus Canon ZR700 -> <- Canon GL1

ALL FOUR Sony Recorder -> <- Canopus Canon ZR700 -> <- Canon GL1 X-30,y-20 = R177,G181,B190 X-30,y-20 = R172,G172,B184 X-30,y-20 = R140,G143,B153 X-30,y-20 = R149,G140,B157

Digital Artifacts Prediction Errors that occur during video compression which is inherently “lossy”

WHY LOSSY COMPRESSION Storage has not yet reached the level needed to store the amount of bits needed to be a lossless copy of an original moving image original.

LOSSY CONTINUED A digital equivalent of a single film frame needs to be scanned at around 3000 ppi. A single negative scanned at the closest size of 3400 ppi would give a 28.8 MB image file when saved in tiff format. To transfer this information to a strip of motion picture film, one would need 24 fps x length. So a 2 hour silent film would be 24 fps x (60 sec x 60 min x 2 hrs) = images. At 28.8 MB per image that would require MB or 4.9 TB for storage.

DONT FORGET LOSSY A 90 minutes of raw video footage from a mini-dv tape equals approximately 16 gigabytes of storage space. Single layer DVD’s 4.7 gigs = 70% compression ratio Dual layer DVD’s 8.5 gigs= 47% compression ratio

HOW IT WORKS Compressors use an algorithm to analyze the pixels of an image in a Zig-Zag method. This data is then used to predict the proceeding images.

HOW IT WORKS This is an image showing how motion prediction is accomplished during the compression process. “I” frames are analyzed independently for data content “P” frames can contain image data and motion data “B” frames can contain image data and motion data

MORE EXAMPLES Now that we know a little bit about how video is compressed, lets look at some comparisons.

RAW COMPARISON Canon ZR700 DVD Canon ZR700 RAW

RAW COMPARISON Canon ZR700 DVD Canon ZR700 RAW X-30,y-20 = R172,G172,B184X-30,y-20 = R170,G170,B182

RAW COMPARISON Canon ZR700 RAW X-30,y-20 = R170,G170,B182X-30,y-20 = R140,G143,B153 Sony Recorder

RAW COMPARISON Canon ZR700 RAWSony Recorder

RAW COMPARISON Canon ZR700 RAW Sony Recorder 400% enlargement

RECOMMENDATIONS Use a camcorder with A/V inputs Store at least three copies –Original –Mini-dv –DVD

THINGS TO REMEMBER Find bench test/technical reviews Having more than one format is important Remember to plan for the future –Bluray and HDDVD hold 6-10 times more than single layer DVDs

Questions Anyone?